chore: update flake.lock

[mrcjkb]

Automated changes by the update-flake-lock GitHub Action.

Flake lock file updates:

• Updated input 'neovim-nightly':
    'github:neovim/neovim/36552adb39edff2d909743f16c1f061bc74b5c4e?dir=contrib' (2023-12-14)
  → 'github:neovim/neovim/f4f7e294695abe7837af62b68564114de7abd0b4?dir=contrib' (2023-12-15)
• Updated input 'nixpkgs':
    'github:nixos/nixpkgs/e97b3e4186bcadf0ef1b6be22b8558eab1cdeb5d' (2023-12-11)
  → 'github:nixos/nixpkgs/aa9d4729cbc99dabacb50e3994dcefb3ea0f7447' (2023-12-14)

Running GitHub Actions on this PR

GitHub Actions will not run workflows on pull requests which are opened by a GitHub Action.

To run GitHub Actions workflows on this PR, run:

git branch -D update_flake_lock_action
git fetch origin
git checkout update_flake_lock_action
git commit --amend --no-edit
git push origin update_flake_lock_action --force